치약 내 불소의 생리적 가용능 평가

Objectives : The aims of this study were to determine the total fluoride concentration and bioavailable fluoride concentration in different toothpastes, based on a newly suggested method by the International Organization for Standardization (ISO), and to compare the measured concentrations with the concentrations written on the packaging. Methods : The concentrations of total fluoride (TF) and bioavailable fluoride (BF) were measured in six toothpastes. For the TF measurement, 1 g of each toothpaste was mixed with dipotassium hydrogen phosphate (K2HPO4), and hydrogen chloride (HCl) was placed. After 24 hours, the samples were centrifuged and total ionic strength adjustment buffer (TISAB) solution was added. For the BF measurement, the toothpaste was mixed with K2HPO4 for only 1 minute. The samples were centrifuged, and then HCl was placed and allowed to stand for 24 hours. The TISAB solution was added subsequently. The concentration of fluoride ions was measured using a fluoride ion-selective electrode and calculated against a standard curve. Results : The six toothpastes were composed of different fluoride compounds and abrasives. The measured TF concentration ranged from 624.99 ppm to 1,353.00 ppm, and the similarity to the declared fluoride concentration ranged from 53.48% to 93.31%. The measured BF concentration ranged from 587.61 ppm to 1,360.05 ppm, and the similarity to the expected fluoride concentration ranged from 41.97% to 93.80%. Two samples were clearly separated when the samples were centrifuged, whereas the remaining four samples had unclear supernatants. The clearly separated toothpastes (i.e., toothpastes 5 and 6) had BF concentrations that were similar to or lower than the declared fluoride concentrations and the measured TF concentrations. However, the unclearly separated toothpastes showed inconsistent relationships between the measured TF and BF concentrations. Conclusions : The measured TF and BF concentrations of the six toothpastes did not reach the expected fluoride concentration. This finding resulted from the different compositions and forms of the toothpastes. Therefore, the properties of toothpastes need to be considered when measuring their fluoride concentrations.ope

Assessment of Acidogenic Potential for Dental Biofilms by Periodontal Health Condition

The aim of this retrospective study was to evaluate the relationship between periodontal health condition and the results of a new method such as Cariview which could evaluate the acidity of dental biofilms. Fifty four subjects more than 20 years old were selected for the candidates of this study. The periodontal health conditions of the candidates were divided into 4 groups according to the assessment of X-ray and Quantitative Light-induced Fluorescence-Digital (QLF-D; Inspektor Research Systems BV) images; gingivitis, slight periodontitis, moderate periodontitis, severe periodontitis. The biofilm acidogenicity of each subject was examined using Cariview (All in ONE BIO) according to manufacturer’s instruction, and the Cariview score was calculated. The mean differences of Cariview score between 4 groups of periodontal health condition were examined by ANCOVA test with the covariance of decayed, missing, and filled teeth (DMFT) index. As a result, the mean Cariview score was different, however it was not significantly different from the 4 groups (p=0.12). The mean score was the lowest in the gingivitis group (40.54±11.01), and the highest in slight periodontitis group (57.26±20.51). In conclusion, the significant mean differences were not confirmed in Cariview score according to the periodontal health condition.ope

치태의 산생성 능력을 이용한 새로운 우식활성검사법의 임상적 활용 가능성 평가

Objectives : This study was aimed at evaluating the clinical usability of a new caries activity test (Cariview®), which was based on the acidogenic potential of plaque by evaluating it's correlation with the DMFT index and comparing the results of Cariview® with those of previous caries activity tests in an adult group. Methods : Teeth of 74 subjects were examined, and the DMFT index was calculated according to World Health Organization (WHO) criteria to determine the past caries experience. Caries activity tests were performed according to manufacturer's instructions. For Cariview® test, plaque samples were collected from the tooth surface by using a sterile cotton swab and incubated at 37℃ for 48 h; an indicator was added to observe the color changes according to the plaque acidogenicity. The subjects were classified into three groups (Low, Moderate, High) according to the level of caries risk. The data were assessed using one-way ANOVA to compare the caries experiences of risk groups according to the caries activity test results, and the relationships between the caries activity tests and the DMFT index were evaluated. Results : The overall mean DMFT index was 5.70±4.42. There was a significant difference in the DMFT index among the caries risk groups (Low, Moderate, High) according to the Cariview® test result (P=0.036). Further, there was a positive correlation between the Cariview® score and the DMFT index (r=0.23, P=0.047) and between the Cariview® score and the previous caries activity tests score (P<0.01). Conclusions : The new caries activity test (Cariview®) can be easily used at dental clinics and enables precise caries risk assessment.ope

Influence of TiO2 Concentrations and Irradiation Lights on the Photocatalytic Reaction for Inhibiting Growth of Streptococcus mutans

The aim of this study was to evaluate influences of titanium dioxide (TiO2) concentrations and irradiation times on growth of Streptococcus mutanswhen irradiated by visible light (405 nm wavelength) and by ultraviolet light (254 nm wavelength). To find the optimal antibacterial concentration ofTiO2, 0.01, 0.1, 1.0, and 10.0 mg/ml TiO2 suspension was prepared with sterilized distilled water. S. mutans cultured media was added to TiO2solution to set the final cell count to 104 CFU/ml. The photocatalytic reaction was induced by irradiating 254 nm and 405 nm lights for 10 minutes. To compare the bactericidal activities according to irradiation times, all photocatalytic reaction was carried out with 0.1 mg/ml TiO2 for 0, 10, 20,30, and 40 minutes with both lights. After the photocatalytic reaction, 100 μm of the reaction mixture was immediately plated on brain heart infusionagar. These plates were placed at 5% CO2, 37oC, for 24 hours and the bacterial colonies were counted. All experiments were performed inquintuplicate. One-way ANOVA was used to determine whether there were any significant differences between the TiO2 concentrations or theirradiation times. The most effective concentration of TiO2 for its photocatalytic bactericidal effect on S. mutans was 0.1 mg/ml when irradiated with254 nm and 405 nm lights. The longer the irradiation time, the bigger the bactericidal effect for both wavelengths. Over 99% of bacteria in theinoculum were killed after irradiation with 254 nm for 20 minutes and with 405 nm for 40 minutes. In conclusion, a photocatalytic reaction of TiO2induced by visible light of 405 nm constitutes the bactericidal effect on S. mutans.ope

Antibacterial effect of Zingiberaceae extracts mediated photodynamic therapy on Streptococcus mutans

Purpose: This study evaluated the antibacterial effects of curcuma, ginger, and finger root extracts in water-soluble powder on planktonic Streptococcus mutans(S.mutans), which is known to cause dental caries, in order to confirm whether these extracts could perform as photosensitizers for the effects of photodynamic therapy (PDT). Methods: This study used the strain of streptococcus mutans ATCC 25175 distributed by the Korean Collection for Type Cultures of the Korea Research Institute of Bioscience & Biotechnology. Commercial edible curcuma, ginger and finger root were used as the natural extracts for the use of photosensitizer. To extract organic solvent, 3 g of each powder was mixed in $30m{\ell}$ 수식 이미지 of dimethyl sulfoxide (DMSO, VWR, Germany) before extraction. $1.8m{\ell}$ 수식 이미지 of the photosensitizer solution, manufactured in the concentrations of 5, 0.5, and $0.05mg/m{\ell}$ 수식 이미지, was mixed with $0.2m{\ell}$ 수식 이미지 of the S. mutans culture medium that had been cultured for 2 days. To induce the photodynamic reaction, Qraycam (AIOBIO, Seoul, Korea) equipped with 405 nm LED was used to expose light for 5 minutes to irradiate 59 nW energy for 300 seconds. Results: Compared with the case with no light, a higher photodynamic therapeutic effect was confirmed with $0.05mg/m{\ell}$ 수식 이미지 curcuma powder extract, the concentration of $0.5mg/m{\ell}$ 수식 이미지 and LED light of 405 nm wavelength (p=0.000, p=0.003). $0.05mg/m{\ell}$ 수식 이미지 of curcuma powder extract and the concentration of $0.5mg/m{\ell}$ 수식 이미지 showed 100% antibacterial effect when exposed to light, whereas the concentration of $5mg/m{\ell}$ 수식 이미지 showed 11.95% antibacterial effect. When exposed to light, $0.05mg/m{\ell}$ 수식 이미지 of ginger powder extract showed an antibacterial effect which didn't statistically decrease. The concentrations of $0.5mg/m{\ell}$ 수식 이미지 and $5mg/m{\ell}$ 수식 이미지 did not show any antibacterial effects. As a result of examining any photodynamic therapeutic effects of finger root powder extract on S. mutans, no statistically significant effect was found. Conclusion: The curcuma powder extract is expected to perform as a photosensitizer. Even though belonging to the same ginger family, ginger powder and finger root powder seem difficult to perform as photosensitizer.ope

Short-term improvement of masticatory function after implant restoration

PURPOSE: Dental implants present several advantages over other tooth replacement options. However, there has been little research on masticatory function in relation to implant treatment. Therefore, the aim of the present study was to evaluate the improvement of masticatory function two weeks after implant restoration. METHODS: Masticatory ability was evaluated with the subjective food intake ability (FIA) and objective mixing ability index (MAI) methods. Fifty-four subjects with first and second missing molars completed the study. The subjects were asked to complete a self-reported questionnaire about 30 different food items, and to chew wax samples 10 times both before and two weeks after implant restoration. A total of 108 waxes were analyzed with an image analysis program. RESULTS: Dental implant restoration for lost molar teeth on one side increased the FIA score by 9.0% (P<0.0001). The MAI score also increased, by 14.3% after implant restoration (P<0.0001). Comparison between the good and poor mastication groups, which were subdivided based on the median MAI score before implant restoration, showed that the FIA score of the poor group was enhanced 1.1-fold while its MAI score was enhanced 2.0-fold two weeks after an implant surgery. CONCLUSIONS: Using the FIA and MAI assessment methods, this study showed that masticatory function was improved two weeks after implant restoration. In particular, the enhancement of masticatory function by implant restoration was greater in patients with relatively poor initial mastication than in those with good initial mastication.ope

In vitro quantification of occlusal caries lesion using QLF-D, ICDAS, and DIAGNOdent

Objectives : To compare the QLF-D method and the ICDAS and DIAGNOdent techniques for in vitro quantification of occlusal caries and to assess the histological features of the caries. Methods : One hundred and twenty-two extracted permanent teeth were selected, and the site of interest on the occlusal surface was examined using each detection method. The occlusal sites were classified according to the ICDAS II criteria based on the decision taken by two investigators, who have taken the ICDAS E-learning course. The examined site was then measured using the DIAGNOdent, and the peak value was recorded. In addition, by using the QLF-D, the occlusal site was photographed to obtain the ΔFmax value. After all assessments were performed, the occlusal sites were vertically sectioned in order to assess the histological features. This was considered the gold standard. The histological criteria were graded using a 4-point scale as follows: S=sound (n=21), E1=limited enamel caries (n=27), E2=caries extending to the dento-enamel junction (n=49), D=caries involving the dentine (n=25). Results : An ICDAS code between 0 and 4 was assigned to all the occlusal sites, and this revealed the QLF-D value, which was between -95 to 0. The DIAGNOdent value was between 8 and 99. The correlation values of QLF-D, ICDAS, and DIAGNOdent with the histological features were 0.68, 0.58, and 0.46, respectively (P<0.01). A highly significant correlation was observed between QLF-D and the gold standard, which showed a moderate correlation and an acceptable correlation was observed with ICDAS (r=0.75, P<0.01). A statistically significant difference was observed in the average QLF-D values of each histological grade i.e., -28.5 (S), -53.7 (E1), -68.1 (E2), and -84.4 (D). Conclusions : The QLF-D showed a significant correlation with the ICDAS and histological features. Therefore, visual inspection with QLF-D would improve the detection accuracy and ensure early diagnosis of dental caries.ope

Lesion activity assessment of early caries using dye-enhanced quantitative light-induced fluorescence

We aimed to determine whether dye-enhanced quantitative light-induced fluorescence (DEQLF), wherein porous structure of caries lesions is stained with a fluorescent dye, could quantitatively distinguish between active and inactive caries. A total of 126 bovine specimens were prepared to artificially simulate caries activity. Active caries were demineralized with 1% carbopol solution for 3 (A3), 5 (A5), and 10 days (A10). For inactive caries, half specimens in each group were remineralized with 2% NaF and reallocated into three groups (I3, I5, and I10, respectively). Wet specimens were dried with compressed air for 10 s and then dyed with 100-µM sodium fluorescein for 10 s. Fluorescence images of speicmens were captured with a QLF-digital 2 + Biluminator. Fluorescence intensity (ΔG) was measured in fluorescence images of dyed specimens. ΔG between active and inactive groups was compared using independent t-test, and ΔG among active groups (or inactive groups) were compared using ANOVA (α = 0.05). ΔG in the active groups was 33.7-59.0 higher than that in the inactive groups (P < 0.001). Except between I3 and I5, there was significant differences in ΔG according to the demineralization period (P < 0.001). DEQLF might be used to evaluate early caries activity, and longitudinally monitor changes in lesion activity.ope

The antibacterial effect of xanthorrhizol as an endodontic irrigant on Enterococcus faecalis

Objectives: The aim of this study was to evaluate the antibacterial effect of xanthorrhizol (XTZ) on E. faecalis, compared with 2% chlorhexidine (CHX). Materials and Methods: Normal physiological state (NS), starvation state (SS), and alkalization state (AS) of E. faecalis were used. A solution containing 1% XTZ in 30% ethanol, 1% dimethyl sulfoxide (DMSO), and 100 mg/ml sodium methyl cocoyl taurate was used and is referred to as Xan in this study. To determine the minimal bactericidal concentration (MBC) of Xan and CHX, 500μl of E. faecalis (NS and two stress states) was added to a microtube containing 500μl of serial 2-fold dilutions of 1% Xan and 2% CHX (1:2-1:128). The MBC of each antimicrobial was determined by the plate count method. Results: The antibacterial effect of Xan was more effective on E. faecalis in AS than in the other states (NS, SS) at 0.125% Xan and 0.03325% Xan (P<0.05). In contrast, the antibacterial effect of CHX was more effective against E. faecalis in SS than the other states (NS, AS) at 0.0625% CHX (P<0.05). In SS, the antibacterial effect of CHX was more effective than that of Xan at 0.125% and 0.0625% (P<0.05). However, in AS, the antibacterial effect of Xan was more effective than that of CHX at 0.0625% and 0.03325% (P<0.05). Conclusions: In endodontic retreatment cases in which it is important to effectively remove E. faecalis from the infected root canal, Xan may be more suitable when combined with NaOCl than CHX.ope

Antibacterial effect caused by the combination of xanthorrhizol and several surfactants

Objectives. The aim of this study was to evaluate the antibacterial effect caused by a combination of Xanthorrhizol (Xan) and several surfactants on planktonic and biofilm of S. mutans. An additional aim was to confirm the safety of a combined solution as a MTT cell viability assay. Methods. The Xan, isolated from Indonesian folk medicinal plants, was used at concentrations of 12.5 and 25 ppm. Ethanol (12.5%) was used as a solvent, while sodium lauryl sulfate (SLS; 200, 250 ppm) and sodium methyl cocoyl taurate (Tau; 250, 300 ppm) were used as surfactants. The planktonic S. mutans ATCC 25175 (2×107 CFU/ml) was mixed with Xan containing surfactant and ethanol for 5 minutes, and counted as colonies of live cells. The antibacterial effect of Xan was tested by a biofilm model with S. mutans, which was used with the saliva-media, hydroxyapatite (HA) disc and BHI broth. The cultured biofilm on HA disc was exposed to the treatment solutions mixed with Xan, surfactants, and ethanol for 5 minutes. This process was repeated at 16, 40, 64 hours later. MTT assays were carried out to evaluate cell viability and cell proliferation after exposure of Xan. Results. Antibacterial effect of Xan on planktonic S. mutans significantly increased when applied with 200 ppm SLS and 300 ppm Tau (p<0.05). The formation of S. mutans biofilm was inhibited by 25 ppm Xan mixed with 250 ppm SLS or 300 ppm Tau. In addition, the cytotoxicity of Xan was similar to that of 0.2% chlorhexidine oral rinse. Conclusions. The solutions of Xanthorrhizol with surfactants such as SLS and Tau showed significant antimicrobial effect on planktonic and biofilm cells of S. mutans (p＜0.05). These solutions also exhibited biological safety similar to chlorhexidine oral rinseope